nl80211: fix dumpit error path RTNL deadlocks
commit ea90e0dc8cecba6359b481e24d9c37160f6f524f upstream. Sowmini pointed out Dmitry's RTNL deadlock report to me, and it turns out to be perfectly accurate - there are various error paths that miss unlock of the RTNL. To fix those, change the locking a bit to not be conditional in all those nl80211_prepare_*_dump() functions, but make those require the RTNL to start with, and fix the buggy error paths. This also let me use sparse (by appropriately overriding the rtnl_lock/rtnl_unlock functions) to validate the changes. Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johannes Berg
Greg Kroah-Hartman
parent
7922c1becb
commit
74c8dd066c
@ -492,21 +492,17 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
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{
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int err;
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rtnl_lock();
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if (!cb->args[0]) {
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err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
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nl80211_fam.attrbuf, nl80211_fam.maxattr,
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nl80211_policy);
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if (err)
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goto out_unlock;
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return err;
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*wdev = __cfg80211_wdev_from_attrs(sock_net(skb->sk),
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nl80211_fam.attrbuf);
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if (IS_ERR(*wdev)) {
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err = PTR_ERR(*wdev);
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goto out_unlock;
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}
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if (IS_ERR(*wdev))
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return PTR_ERR(*wdev);
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*rdev = wiphy_to_rdev((*wdev)->wiphy);
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/* 0 is the first index - add 1 to parse only once */
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cb->args[0] = (*rdev)->wiphy_idx + 1;
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@ -516,10 +512,8 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
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struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0] - 1);
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struct wireless_dev *tmp;
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if (!wiphy) {
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err = -ENODEV;
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goto out_unlock;
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}
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if (!wiphy)
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return -ENODEV;
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*rdev = wiphy_to_rdev(wiphy);
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*wdev = NULL;
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@ -530,21 +524,11 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
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}
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}
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if (!*wdev) {
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err = -ENODEV;
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goto out_unlock;
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}
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if (!*wdev)
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return -ENODEV;
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}
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return 0;
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out_unlock:
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rtnl_unlock();
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return err;
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}
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static void nl80211_finish_wdev_dump(struct cfg80211_registered_device *rdev)
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{
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rtnl_unlock();
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}
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/* IE validation */
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@ -3884,9 +3868,10 @@ static int nl80211_dump_station(struct sk_buff *skb,
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int sta_idx = cb->args[2];
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int err;
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rtnl_lock();
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err = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
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if (err)
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return err;
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goto out_err;
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if (!wdev->netdev) {
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err = -EINVAL;
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@ -3922,7 +3907,7 @@ static int nl80211_dump_station(struct sk_buff *skb,
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cb->args[2] = sta_idx;
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err = skb->len;
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out_err:
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nl80211_finish_wdev_dump(rdev);
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rtnl_unlock();
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return err;
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}
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@ -4639,9 +4624,10 @@ static int nl80211_dump_mpath(struct sk_buff *skb,
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int path_idx = cb->args[2];
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int err;
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rtnl_lock();
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err = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
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if (err)
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return err;
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goto out_err;
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if (!rdev->ops->dump_mpath) {
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err = -EOPNOTSUPP;
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@ -4675,7 +4661,7 @@ static int nl80211_dump_mpath(struct sk_buff *skb,
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cb->args[2] = path_idx;
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err = skb->len;
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out_err:
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nl80211_finish_wdev_dump(rdev);
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rtnl_unlock();
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return err;
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}
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@ -4835,9 +4821,10 @@ static int nl80211_dump_mpp(struct sk_buff *skb,
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int path_idx = cb->args[2];
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int err;
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rtnl_lock();
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err = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
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if (err)
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return err;
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goto out_err;
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if (!rdev->ops->dump_mpp) {
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err = -EOPNOTSUPP;
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@ -4870,7 +4857,7 @@ static int nl80211_dump_mpp(struct sk_buff *skb,
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cb->args[2] = path_idx;
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err = skb->len;
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out_err:
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nl80211_finish_wdev_dump(rdev);
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rtnl_unlock();
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return err;
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}
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@ -6806,9 +6793,12 @@ static int nl80211_dump_scan(struct sk_buff *skb, struct netlink_callback *cb)
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int start = cb->args[2], idx = 0;
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int err;
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rtnl_lock();
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err = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
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if (err)
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if (err) {
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rtnl_unlock();
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return err;
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}
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wdev_lock(wdev);
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spin_lock_bh(&rdev->bss_lock);
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@ -6831,7 +6821,7 @@ static int nl80211_dump_scan(struct sk_buff *skb, struct netlink_callback *cb)
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wdev_unlock(wdev);
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cb->args[2] = idx;
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nl80211_finish_wdev_dump(rdev);
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rtnl_unlock();
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return skb->len;
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}
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@ -6915,9 +6905,10 @@ static int nl80211_dump_survey(struct sk_buff *skb, struct netlink_callback *cb)
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int res;
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bool radio_stats;
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rtnl_lock();
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res = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
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if (res)
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return res;
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goto out_err;
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/* prepare_wdev_dump parsed the attributes */
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radio_stats = nl80211_fam.attrbuf[NL80211_ATTR_SURVEY_RADIO_STATS];
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@ -6958,7 +6949,7 @@ static int nl80211_dump_survey(struct sk_buff *skb, struct netlink_callback *cb)
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cb->args[2] = survey_idx;
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res = skb->len;
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out_err:
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nl80211_finish_wdev_dump(rdev);
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rtnl_unlock();
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return res;
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}
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@ -10158,17 +10149,13 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
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void *data = NULL;
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unsigned int data_len = 0;
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rtnl_lock();
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if (cb->args[0]) {
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/* subtract the 1 again here */
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struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0] - 1);
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struct wireless_dev *tmp;
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if (!wiphy) {
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err = -ENODEV;
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goto out_unlock;
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}
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if (!wiphy)
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return -ENODEV;
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*rdev = wiphy_to_rdev(wiphy);
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*wdev = NULL;
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@ -10189,13 +10176,11 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
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nl80211_fam.attrbuf, nl80211_fam.maxattr,
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nl80211_policy);
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if (err)
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goto out_unlock;
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return err;
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if (!nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_ID] ||
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!nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD]) {
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err = -EINVAL;
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goto out_unlock;
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}
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!nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD])
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return -EINVAL;
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*wdev = __cfg80211_wdev_from_attrs(sock_net(skb->sk),
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nl80211_fam.attrbuf);
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@ -10204,10 +10189,8 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
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*rdev = __cfg80211_rdev_from_attrs(sock_net(skb->sk),
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nl80211_fam.attrbuf);
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if (IS_ERR(*rdev)) {
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err = PTR_ERR(*rdev);
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goto out_unlock;
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}
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if (IS_ERR(*rdev))
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return PTR_ERR(*rdev);
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vid = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_ID]);
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subcmd = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD]);
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@ -10220,19 +10203,15 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
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if (vcmd->info.vendor_id != vid || vcmd->info.subcmd != subcmd)
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continue;
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if (!vcmd->dumpit) {
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err = -EOPNOTSUPP;
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goto out_unlock;
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}
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if (!vcmd->dumpit)
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return -EOPNOTSUPP;
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vcmd_idx = i;
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break;
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}
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if (vcmd_idx < 0) {
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err = -EOPNOTSUPP;
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goto out_unlock;
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}
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if (vcmd_idx < 0)
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return -EOPNOTSUPP;
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if (nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]) {
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data = nla_data(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]);
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@ -10249,9 +10228,6 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
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/* keep rtnl locked in successful case */
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return 0;
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out_unlock:
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rtnl_unlock();
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return err;
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}
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static int nl80211_vendor_cmd_dump(struct sk_buff *skb,
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@ -10266,9 +10242,10 @@ static int nl80211_vendor_cmd_dump(struct sk_buff *skb,
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int err;
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struct nlattr *vendor_data;
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rtnl_lock();
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err = nl80211_prepare_vendor_dump(skb, cb, &rdev, &wdev);
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if (err)
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return err;
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goto out;
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vcmd_idx = cb->args[2];
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data = (void *)cb->args[3];
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@ -10277,18 +10254,26 @@ static int nl80211_vendor_cmd_dump(struct sk_buff *skb,
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if (vcmd->flags & (WIPHY_VENDOR_CMD_NEED_WDEV |
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WIPHY_VENDOR_CMD_NEED_NETDEV)) {
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if (!wdev)
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return -EINVAL;
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if (!wdev) {
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err = -EINVAL;
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goto out;
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}
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if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_NETDEV &&
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!wdev->netdev)
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return -EINVAL;
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!wdev->netdev) {
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err = -EINVAL;
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goto out;
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}
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if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_RUNNING) {
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if (wdev->netdev &&
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!netif_running(wdev->netdev))
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return -ENETDOWN;
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if (!wdev->netdev && !wdev->p2p_started)
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return -ENETDOWN;
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!netif_running(wdev->netdev)) {
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err = -ENETDOWN;
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goto out;
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}
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if (!wdev->netdev && !wdev->p2p_started) {
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err = -ENETDOWN;
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goto out;
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}
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}
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}
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